The Kenworth Model T440 tractor ranges in GVW from 33,000 pounds to 68,000 pounds. Options include the Kenworth extended day cab, which has an additional six inches of length and five inches of cab height compared to the day cab, and the 38-in. Kenworth AeroCab sleeper. The 2010 Paccar PX-8 engine is standard with ratings to 350 hp and 1,000 lb.-ft. of torque. The optional 9-liter, 2010 Cummins ISL engine is rated to 380 hp and 1,300 lb.-ft. of torque. The T440 offers 6-, 9-, 10-, 11-, and 13-speed manual and 5- and 6-speed automatic transmissions, 12,000 to 22,000 lb. rated front axles, 21,000 to 30,000 lb. rated single rear axles, and 40,000 to 46,000 lb. rated tandem rear axles.